Charles Kagiri

15+ years of experience engineering high-performance, end-to-end systems across Silicon Valley (Foursquare, FaunaDB) and the Kenyan supply-chain and fintech sector. Vast experience of bridging the gap between complex data engineering and intuitive frontend architecture. Proven track record of leading full-stack teams to deliver everything from pixel-perfect, data-heavy React dashboards to hardened, Zero-Trust backend infrastructures

Senior Backend Architect (Contract) at Tangazo Letu (2025-11 – Present)

Fintech & Core Banking Solutions

• Led E2E integration of ISO 20022 (Pesalink) gateway, handling pacs.008 and pacs.002 message orchestration between multiple financial institutions.
• Architectured a Zero-Trust 'Token Chaining' model using single-use JWTs and AES-256-GCM encryption, eliminating session hijacking risk for high-stakes payment gateways.
• Refactored and modernized a legacy ESB model, optimizing for headless containerized deployments and reducing latency.
• Engineered an asynchronous auditing engine using PostgreSQL timescaleDB & JSONB with PII masking to ensure regulatory compliance without impacting transaction throughput.

Career Break (2025-06 – 2025-08)

Well-being & Reflection

• Dedicated time for self-reflection and family after a decade of continuous technical delivery and leadership.

Senior Fullstack Software Engineer at Foursquare (2019-02 – 2025-05)

• Engineered and maintained critical features for Foursquare's market-leading marketing and attribution application, utilizing React and Java Spring Micro-Services to process offline attribution for a global brand base.
• Acted as the primary technical liaison between data science and frontend teams, maintaining 99.9% SLAs through proactive observability and alerting.
• Built a star-schema UI tool for complex query generation, cutting custom report configuration time by more than 50% for non-technical users.
• Designed an asynchronous reporting client using AWS Lambda, DynamoDB, SNS, and SQS, reducing client report turnaround by 70%.
• Managed a documentation system upgrade and rebrand from Jekyll to Gatsby as part of a company-wide modernization effort, ensuring zero data loss.
• Developed a multi-region promotions app for high-profile clients (e.g., Hellmann's), delivering dynamic theming and localization for USA and Canada markets.

Full Stack Software Engineer at Fauna DB (2018-05 – 2018-11)

• Led the development of the initial FaunaDB Web Explorer POC using React/TypeScript, managing a team of three to meet a 4-month deadline.
• Collaborated with Salesforce engineers to integrate sign-ups via Pardot, resulting in a significant increase in user prospects.

Fullstack Software Engineer at Herufi Africa (2016-03 – 2018-02)

• Architected Angular-based sales and inventory systems and led a team of four frontend developers.
• Engineered an offline-first Android app for field sales with intelligent referential sync and Bluetooth receipt printing.

Software Engineer at Caytree Partners LLC (2014-04 – 2016-02)

• Developed Caytree Marketplace, onboarding 500+ businesses with integrated M-Pesa and PesaPal payment systems.

Software Engineer at Virtual City Limited (2011-11 – 2013-10)

• Developed.NET enterprise applications and server-side performance reports using SQL Server Reporting Engine (SSRS), MongoDB and RabbitMQ.

Bachelor's Degree in Pure Mathematics and Computer Science – Jomo Kenyatta University of Agriculture and Technology (JKUAT) (2007 – 2011)